Synergistic effect of EVA copolymer and sodium desulfurization ash on the printing performance of high volume blast furnace slag mixtures

Considering the long-term development of digital construction, a cost-effective and environmental printing material was designed with blast furnace slag as main cementitious material and sodium desulfurization ash as activator. However, weak alkaline environment lead to the insufficient 3D printability (e.g. yield stress, viscosity). Ethylene/vinyl acetate copolymer (EVA) was used to make up this defect, and it was found that there was a synergistic effect between EVA and sodium desulfurization ash (NS), which is beneficial to the improvement of the printing performance. The synergistic effect of EVA and NS was investigated in terms of fresh, hardened and microstructure properties. Experimental results show that under varying resting times and shear rates, the addition of 0.6-1.6% (i.e.by mass of binder) EVA could increase the yield stress and apparent viscosity of HVGS. Moreover, it was also found that the addition of EVA could help improve the polymerization degree of printing materials and increase the compressive strength of 28d by about 22%. To verify the practical value of the printing material, an industrial product was printed, and the maximum number of continuous printing layers can be up to 30 layers.